具雙伺服馬達之直線式吹瓶機的開關模機構設計,有兩組水平反方向運動模板及一組底模垂直昇降動作。利用獨立伺服馬達兩組為動力,透過兩組相同共軛凸輪產生搖臂30度擺動,再經過兩組連桿機構驅動,獨立控制兩組模板開關動作,其中一組連桿機構同時為底模動力源,驅動四連桿機構搭配一板凸輪,使開關模與底模同時動作。本文依據向量迴路法,牛頓運動定律,建立運動分析、靜力分析的數學模式,求得輸入力矩、桿件及接頭的作用力,再依據連桿運動之限制條件及設計需求,以基本凸輪曲線(MS)設計底模凸輪曲線,接著使用包絡線原理求出凸輪輪廓外型。最後以單伺服開關模機構與雙伺服開關模機構個桿件及接頭受力做比較。
For the design on dual-servo motor with clamp open/close cam linkages mechanism of one linear type blow-molding machine, there are two sets of cams with horizontal movement in the opposite direction and a bottom mold template for vertical moving action. The use of two independent servo motors as driving force generates rocker arm 30 degrees from the conjugate cams. The driving force goes through two groups of linkage mechanism to move clamp templates independently. One group of linkage mechanism drives movement of bottom mold through four-bar linkage with a plate cam correspondingly to clamp open/close. In this paper, based on the Vector Loop method and Newton's laws of motion, we establish motion analysis, static analysis in mathematical formula to calculate input torque and force on linkage and connectors. Furthermore, we consider boundary condition of linkage mechanism and design requirements, and refer to basic cam curve (MS) to form bottom mold design cam curve. Then we utilize theory of envelope to calculate profile of cam. Finally, we compare related linkage and connectors of single-servo mechanism with dual-servo mechanism.